The accurate, precise, and reliable measurement of the velocity and direction of the flow of fluids such as gases and liquids is of great importance. For example, in meteorology, the speed and direction of wind (e.g., the flow of ambient air), are important parameters for the classification, forecast, and research of weather and climate conditions. In industrial applications, the measurement of the flow velocity and direction of fluids is imperative for system control and monitoring, as well as for the determination of trade quantities.
However, the measurement of the velocity and direction of fluid flows can be challenging. Current meters for flow velocity and flow direction of gases and liquids are usually limited by the fact that either (a) two separate instruments for flow speed and flow direction are required resulting in increased complexity and cost and/or (b) single instrument measuring devices are restricted by high power consumption, complexity, large dimensions, and/or reduced resilience with regard to external factors such as animal interaction, dust, icing, hail, and/or other factors.
In the case of measuring the velocity and direction of wind flow, rotating wind speed meters, such as cup anemometers, generally measure wind speed, but not wind direction. Further, cup anemometers require extensive and frequent calibration and are prone to mechanical failure due to moving and/or rotating parts. Sonic anemometers, which can measure both wind speed and direction, have limited operational stand-alone lifetime due to high power consumption. In addition, high volume requirements of sonic anemometers, as needed for multiple sonic paths, further reduce usability in applications where limited space for installation and transport is required.